Novel serum protein biomarker panel revealed by mass spectrometry and its prognostic value in breast cancer

Abstract

IntroductionSerum profiling using proteomic techniques has great potential to detect biomarkers that might improve diagnosis and predict outcome for breast cancer patients (BC). This study used surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry (MS) to identify differentially expressed proteins in sera from BC and healthy volunteers (HV), with the goal of developing a new prognostic biomarker panel.MethodsTraining set serum samples from 99 BC and 51 HV subjects were applied to four adsorptive chip surfaces (anion-exchange, cation-exchange, hydrophobic, and metal affinity) and analyzed by time-of-flight MS. For validation, 100 independent BC serum samples and 70 HV samples were analyzed similarly. Cluster analysis of protein spectra was performed to identify protein patterns related to BC and HV groups. Univariate and multivariate statistical analyses were used to develop a protein panel to distinguish breast cancer sera from healthy sera, and its prognostic potential was evaluated.ResultsFrom 51 protein peaks that were significantly up- or downregulated in BC patients by univariate analysis, binary logistic regression yielded five protein peaks that together classified BC and HV with a receiver operating characteristic (ROC) area-under-the-curve value of 0.961. Validation on an independent patient cohort confirmed the five-protein parameter (ROC value 0.939). The five-protein parameter showed positive association with large tumor size (P = 0.018) and lymph node involvement (P = 0.016). By matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS, immunoprecipitation and western blotting the proteins were identified as a fragment of apolipoprotein H (ApoH), ApoCI, complement C3a, transthyretin, and ApoAI. Kaplan-Meier analysis on 181 subjects after median follow-up of >5 years demonstrated that the panel significantly predicted disease-free survival (P = 0.005), its efficacy apparently greater in women with estrogen receptor (ER)-negative tumors (n = 50, P = 0.003) compared to ER-positive (n = 131, P = 0.161), although the influence of ER status needs to be confirmed after longer follow-up.ConclusionsProtein mass profiling by MS has revealed five serum proteins which, in combination, can distinguish between serum from women with breast cancer and healthy control subjects with high sensitivity and specificity. The five-protein panel significantly predicts recurrence-free survival in women with ER-negative tumors and may have value in the management of these patients.

An efficient biomarker panel for diagnosis of breast cancer using surface-enhanced laser desorption ionization time-of-flight mass spectrometry

“…Previous studies have reported 4.3, 8.1 and 8.9 kDa proteins as biomarkers of BC; however, these results differ to those of the present study (8,11,22,26). A 3.8 kDa protein, close to m/z 3,972, was reported to be highly sensitive for the diagnosis of BC by Chung et al (12). A number of serumbased candidate biomarkers have been identified in different studies (8,10,22,31).…”

“…Previous studies have reported a number of potential serum biomarkers that may be used to diagnose BC; BC1 (4.3 kDa), BC2 (8.1 kDa) and BC3 (8.9 kDa) (8,9 are as follows: BC1, inter-α-trypsin inhibitor heavy chain H4; BC2, C3a des-arginine-C terminal truncated peptide; and BC3, C3a des-arginine (10). A number of other potential biomarkers have been identified and demonstrated to have high diagnostic accuracy (7,11,12). However, validating these proteins is difficult due to different protocols for sample handling, patient populations and tumor characteristics.…”

Quantitative Profiling of Post-translational Modifications by Immunoaffinity Enrichment and LC-MS/MS in Cancer Serum without Immunodepletion

“…The histological diagnosis of NSCLC patient #4 (with 35 years of smoking history) was squamous cell carcinoma; while the histological diagnosis of #1, #2, and #3 patients (nonsmokers) of NSCLC was adenocarcinoma (Supplemental Table S1). DISCUSSION Extensive effort has been expended on method development for analyzing the serum/plasma proteome to identify potential biomarkers (1,3,26,27). In the current study, we have developed a robust workflow combining PTM motif antibody enrichment and LC-MS/MS analysis for profiling different PTMs.…”

Diagnostic and prognostic significance of serum apolipoprotein C-I in triple-negative breast cancer based on mass spectrometry

“…56 Despite the rapid evolution of MS-based proteomics methods, in terms of resolution power, mass accuracy, accurate quantification, and sequencing speed, together with parallel improvements in bioinformatics tools for analysis of large amounts of data, SELDI-TOF-MS we referred, popularly used in the first decade of 2000, still has a great impact on cancer proteomics to uncover crucial molecular events that drive malignant cells progression or response to therapy in recent years, and could pave the way for the identification of new therapeutic targets with higher sensitivity and resolving power. [57][58][59][60] Apolipoproteins (Apo-) bind lipids to form lipoproteins that transport these lipids through the lymphatic and circulatory systems. Serum and plasma lipoprotein metabolism are regulated and controlled by specific Apo-constituents of various lipoprotein classes, such as apoA-I, apoC-I, apoC-III, apo-H (b 2 glycoprotein), and others.…”